/*
 * Copyright 2010, 2011, 2012, 2013 mapsforge.org
 *
 * This program is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */
package org.mapsforge.core.model;

import java.io.Serializable;

/**
 * A Rectangle represents an immutable set of four double coordinates.
 */
public class Rectangle implements Serializable {
	private static final long serialVersionUID = 1L;

	public final double bottom;
	public final double left;
	public final double right;
	public final double top;

	public Rectangle(double left, double top, double right, double bottom) {
		if (left > right) {
			throw new IllegalArgumentException("left: " + left + ", right: " + right);
		} else if (top > bottom) {
			throw new IllegalArgumentException("top: " + top + ", bottom: " + bottom);
		}

		this.left = left;
		this.top = top;
		this.right = right;
		this.bottom = bottom;
	}

	/**
	 * @return true if this Rectangle contains the given point, false otherwise.
	 */
	public boolean contains(Point point) {
		return this.left <= point.x && this.right >= point.x && this.top <= point.y && this.bottom >= point.y;
	}

	public Rectangle envelope(double padding) {
		return new Rectangle(this.left - padding, this.top - padding, this.right + padding, this.bottom + padding);
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj) {
			return true;
		} else if (!(obj instanceof Rectangle)) {
			return false;
		}
		Rectangle other = (Rectangle) obj;
		if (Double.doubleToLongBits(this.left) != Double.doubleToLongBits(other.left)) {
			return false;
		} else if (Double.doubleToLongBits(this.top) != Double.doubleToLongBits(other.top)) {
			return false;
		} else if (Double.doubleToLongBits(this.right) != Double.doubleToLongBits(other.right)) {
			return false;
		} else if (Double.doubleToLongBits(this.bottom) != Double.doubleToLongBits(other.bottom)) {
			return false;
		}
		return true;
	}

	/**
	 * @return a new Point at the horizontal and vertical center of this Rectangle.
	 */
	public Point getCenter() {
		return new Point(getCenterX(), getCenterY());
	}

	/**
	 * @return the horizontal center of this Rectangle.
	 */
	public double getCenterX() {
		return (this.left + this.right) / 2;
	}

	/**
	 * @return the vertical center of this Rectangle.
	 */
	public double getCenterY() {
		return (this.top + this.bottom) / 2;
	}

	public double getHeight() {
		return this.bottom - this.top;
	}

	public double getWidth() {
		return this.right - this.left;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		long temp;
		temp = Double.doubleToLongBits(this.left);
		result = prime * result + (int) (temp ^ (temp >>> 32));
		temp = Double.doubleToLongBits(this.top);
		result = prime * result + (int) (temp ^ (temp >>> 32));
		temp = Double.doubleToLongBits(this.right);
		result = prime * result + (int) (temp ^ (temp >>> 32));
		temp = Double.doubleToLongBits(this.bottom);
		result = prime * result + (int) (temp ^ (temp >>> 32));
		return result;
	}

	/**
	 * @return true if this Rectangle intersects with the given Rectangle, false otherwise.
	 */
	public boolean intersects(Rectangle rectangle) {
		if (this == rectangle) {
			return true;
		}

		return this.left <= rectangle.right && rectangle.left <= this.right && this.top <= rectangle.bottom
				&& rectangle.top <= this.bottom;
	}

	public boolean intersectsCircle(double pointX, double pointY, double radius) {
		double halfWidth = getWidth() / 2;
		double halfHeight = getHeight() / 2;

		double centerDistanceX = Math.abs(pointX - getCenterX());
		double centerDistanceY = Math.abs(pointY - getCenterY());

		// is the circle is far enough away from the rectangle?
		if (centerDistanceX > halfWidth + radius) {
			return false;
		} else if (centerDistanceY > halfHeight + radius) {
			return false;
		}

		// is the circle close enough to the rectangle?
		if (centerDistanceX <= halfWidth) {
			return true;
		} else if (centerDistanceY <= halfHeight) {
			return true;
		}

		double cornerDistanceX = centerDistanceX - halfWidth;
		double cornerDistanceY = centerDistanceY - halfHeight;
		return cornerDistanceX * cornerDistanceX + cornerDistanceY * cornerDistanceY <= radius * radius;
	}

	public Rectangle shift(Point origin) {
		if (origin.x == 0 && origin.y == 0) {
			return this;
		}
		return new Rectangle(this.left + origin.x, this.top + origin.y, this.right + origin.x, this.bottom + origin.y);
	}

	@Override
	public String toString() {
		StringBuilder stringBuilder = new StringBuilder();
		stringBuilder.append("left=");
		stringBuilder.append(this.left);
		stringBuilder.append(", top=");
		stringBuilder.append(this.top);
		stringBuilder.append(", right=");
		stringBuilder.append(this.right);
		stringBuilder.append(", bottom=");
		stringBuilder.append(this.bottom);
		return stringBuilder.toString();
	}
}
